www.samlexpower.com
1. INTRODUCTION
This unit is an electronic device that converts 12V direct current from a battery to 115V
alternating current. This unit employed the latest power electronics technology that results in
smaller size but higher output power.
The AC output waveform of the this POWER INVERTER is known as “modified sine wave”. It is
a waveform that has characteristics similar to the sine wave shape of utility power. This type of
waveform is suitable for most AC loads, including linear and switching power supplies used in
electronic equipment, transformers, and motors. (See Figure 1).
The modified sine wave has an RMS (root mean square) voltage of 115 volts, which is the same
as standard household power. Most AC voltmeters (both digital and analog) are sensitive to the
average value of the waveform rather than the RMS value. They are calibrated for RMS voltage
under the assumption that the waveform measured will be a pure sine wave. These meters will
not read the RMS voltage of a modified sine wave correctly. They will read about 20 to 30 volts
low when measuring the output of the unit. For accurate measurement of the output voltage of
this unit, use a true RMS reading voltmeter such as a Fluke 87III, Fluke 8060A, Fluke 77/99
series or Beckman 4410.
FIGURE 1:
Modified Sine Wave and Sine Wave Comparison
